Feature Request: Multiple trays

[Bent Hillerkus]

It seems that I can initiate multiple instances of SystemTray, however this package will actually only create the first one.
Atleast on win32 an app can have multiple tray menus.

This feature is useful if an app needs tray icons to convey status information, or if some subaction inside the app requires its own icon.

For example while doing a screen recording, ShareX will add an additional 🔴 to the tray.